SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '84b541ce9f3a8284409db189ae2eacc26537d5b34a9b43f4dffe70f90376a287' 
  AND token = 'mx+RH+pP+2EF36yOIz4PsrVGwqtRr2oZF9Vz3ph+PQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}